2. Frenzy
It's widely expected that Days of Future Past will follow the comic book arc of the Brotherhood of Mutants attempting to assassinate Senator Kelly, which in the future timeline leads to Sentinels running the world and the mutants being placed in interment camps. It's as good a time as any to introduce Joanna Cargill, the kick-ass mutant known as Frenzy, and though we hate to resort to tokenism, there's no denying that she'd be a much-needed ethnic addition to the line-up. More to the point, though, it has a lot of dramatic (and also comic) potential for the 1970s portions of the film, given how race relations changed during America at that point; much like the sly jokes that infused Men in Black 3's time-travel madness, Days of Future Past could similarly engage with real life history in a clever way.